Conventionally, as a magnetic sensor for detecting a weak magnetic field such as geomagnetism, an orthogonal fluxgate magnetic sensor is known. Examples of the orthogonal fluxgate magnetic sensor include those disclosed in Japanese Patent Application Laid-Open Nos. 2005-114489, 2004-271481, 2004-198379, and 2004-184098.
Such an orthogonal fluxgate magnetic sensor comprises a magnetic sensor element including a conductive body, a magnetic body disposed around the conductive body, and a detection coil wound around the magnetic body.
However, the orthogonal fluxgate magnetic sensor having the structure described above has problems in that it is difficult to reduce the size, particularly the thickness, of the magnetic sensor element and that the magnetic sensor element cannot be formed as an IC.
Japanese Patent Application Laid-Open No. 2003-004831 discloses a magnetic sensor including spiral-shaped coils and a rectangular stripe made of a magnetic material and disposed on the coils.
However, in the above magnetic sensor, since the stripe (stripe or strip) of the magnetic material is disposed on the square spiral-shaped coils with 2.5 mm sides, the generated magnetic field become longer in a long axis direction. Therefore, disadvantageously, it is difficult to reduce the size and thickness of the magnetic sensor.